Effect of Pretreatment on Anticorrosive Performance of AZX911 Magnesium Alloy Treated with Anodizing from Phosphate and Ammonium Salt Solution

摘要

The effects of two different pretreatments on the anticorrosive performance of AZX911 magnesium alloy containing 1.0mass% calcium treated with an anodizing from phosphate and ammonium salt solution have been studied. The AZX911 magnesium alloy after anodizing had a lower anticorrosive performance. The lowering of this anticorrosive performance was attributed to the 0.1mass% calcium in the anodized coating. The anticorrosive performance of the AZX911 magnesium alloy was improved by applying a fluoride salt solution in the pretreatment. This fluoride salt solution treatment made it possible to remove calcium close to the surface of the AZX911 magnesium alloy substrate, the calcium content in an anodized coating being decreased. The anticorrosive performance was improved by the anodizing from phosphate and ammonium salt solution with a sacrificial anticorrosive effect.